How do I run a Rake task every time a file is save

Question

How do I run a rake script automatically every time I save a file in Visual Studio? I can create a batch file that wraps the command. And I'd like to trigger it on CTRL + S. But, Visual Studio 2012 doesn't have macros.

JP Boodhoo has done it in many of his screen casts, but hasn't shared the implementation.

---

FYI, my rakefile looks like this

require 'albacore'

desc 'Build Solution'
msbuild :Build do |msb| 
  msb.properties :configuration => :Release 
  msb.targets :Clean, :Build 
  msb.solution = 'ProjoBot.sln' 
end 

desc 'Run Unit Tests' 
mspec :Test do |mspec| 
  mspec.command = 'Lib/Tools/MSpec/mspec-clr4.exe' 
  mspec.assemblies 'Src/Tests/ProjoBot.UnitSpecifications/bin/Release/ProjoBot.UnitSpecifications.dll'
end 

task :default => [:Build, :Test]

Answer 1

There may be some options that integrate with the command line that are ignorant of Visual Studio.

The Ruby/Guard Way

I was playing with the Guard gem last night. You basically install guard and the Guard rake plugin.

gem install guard
gem install guard-rake

You can create a Guard "template", a Guardfile with a plain Rake task in it

guard init rake

You can edit it to watch .cs files in the source directory, for example. (and

guard 'rake', :task => 'default', :run_on_start => false do
  watch(%r{^source/.+\.cs$})
end

Then start Guard

guard

You may need to use -i to turn off this "interactive" mode, which may generate errors on Windows!

guard -i

Guard runs like a little local server, showing logs

12:07:08 - INFO - Guard uses TerminalTitle to send notifications.
12:07:08 - INFO - Starting guard-rake default
12:07:08 - INFO - Guard is now watching at 'D:/temp'
[1] guard(main)>

And if you force a file change (I'm going to touch a fake file I set up in my test directory), you'll get the output of your rake task!

12:07:08 - INFO - Guard uses TerminalTitle to send notifications.
12:07:08 - INFO - Starting guard-rake default
12:07:08 - INFO - Guard is now watching at 'D:/temp'
12:07:54 - INFO - running default
building!...
[1] guard(main)>

The PowerShell Way

There's nothing fancy out there that wraps up filesystem polling triggered actions, but that doesn't mean you can't build your own! I wrote a .\guard.ps1 file that sits in my solution root. It has a FileSystemWatcher and waits for changes in a loop.

$here = Split-Path $MyInvocation.MyCommand.Definition

$watcher = New-Object System.IO.FileSystemWatcher
$watcher.Path = "$here\source"
$watcher.IncludeSubdirectories = $true

while($true) {
  # timeout here lets the console process kill commands and such
  $result = $watcher.WaitForChanged('All', 3000)

  if($result.TimedOut) {
    continue
  }

  # this is where you'd put your rake command
  Write-Host "$($result.ChangeType):: $($result.Name)"

  # and a delay here is good for the CPU :)
  Start-Sleep -Seconds 3
}

You can see it working and printing when you touch or create (New-Item <name> -Type File) files. But, we can also execute rake very simply

rake

PowerShell will just go ahead and execute that as a native command. You could get fancy and make this script look and feel more like Guard (ok, not a lot more, but a little!)

param(
  [string] $path = (Split-Path $MyInvocation.MyCommand.Definition),
  [string] $task = 'default'
)

$watcher = New-Object System.IO.FileSystemWatcher
$watcher.Path = $path
$watcher.IncludeSubdirectories = $true

while($true) {
  $result = $watcher.WaitForChanged('All', 3000)

  if($result.TimedOut) {
    continue
  }

  rake $task

  Start-Sleep -Seconds 3
}

And you'd execute it like this

.\guard.ps1 -Path "$pwd\source" -Task 'build'

Answer 2

I used the External Tools to run a batch file that executes the default Rake task.

@ECHO OFF
rake

I assigned the shortcut key CTRL + S to the tool, so that, when I save, the rake task is triggered! I hope this helps someone looking to do the same thing.